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United States Patent | 5,719,397 |
Hallett ,   et al. | February 17, 1998 |
An apparatus for detecting the presence of a target material such as a multicomponent gas is disclosed. The apparatus includes a source of electromagnetic radiation and a device for dispersing the radiation into different frequency bands for targeting the material at different wavelengths corresponding to absorption bands in the material. Spaced apart optoelectric transducers detect the different frequency bands. A processor detects the changes in the output of the transducers occasioned by partial absorption of the electromagnetic radiation from the source by the target material. Processing means also compensates for temperature variations in the source.
Inventors: | Hallett; William A. (London, GB2); Silver; Joshua D. (Oxford, GB2) |
Assignee: | Spectrasense Limited (Oxford, GB) |
Appl. No.: | 624487 |
Filed: | April 4, 1996 |
PCT Filed: | October 4, 1994 |
PCT NO: | PCT/GB94/02155 |
371 Date: | April 4, 1996 |
102(e) Date: | April 4, 1996 |
PCT PUB.NO.: | WO95/10037 |
PCT PUB. Date: | April 13, 1995 |
Oct 04, 1993[GB] | 9320416 | |
Oct 15, 1993[GB] | 9321275 |
Current U.S. Class: | 250/339.13 |
Intern'l Class: | G01M 021/59 |
Field of Search: | 250/339.13,338.5,343 |
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5223715 | Jun., 1993 | Taylor | 250/343. |
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Automatisierungstechnishe Praxis ATP, vol. 32, No. 7, Jul. 1990, Munchen DE, pp. 338-342, "Entwicklungstendenzen der Betriebsanalysentechnik", see p. 341, right col.; figure 6. Technisches Messen Tm, vol. 52, No. 6, Jun. 1985, Munchen DE, pp. 242-246, G. Schmidtke et al. "Spectroskopische Umweltme technik", see p. 243, left col.; figure 2. IEEE Transactions on Industry Applications, vol. 29, No. 4, Jul. 1993, New York, US, pp. 749-753, Dubaniewicz et al. "Fiber Optics for Atmospheric Mine Monitoring" see p. 750; figures 1,2. Measurement Science and Technology, vol. 3, No. 2, Feb. 1992, Bristol GB, pp. 191-195, S.F. Johnston "Gas Monitors Employing Infrared LEDs", see figures 4,5. |